The number of prisoners jailed for life who were freed on parole has fallen significantly in England and Wales.
More prisoners are also being sent back to jail for breach of conditions
Since April the Parole Board has granted release in one in nine cases. Of 901 requests, 106 were granted, about half the rate of last year.
But its 2005/6 figures show 87 "lifers" who were among 140 returned to prison had committed crimes.
The board says it has exercised greater caution after two violent offenders committed murder after being released.
The annual figures also revealed there were 1,495 lifers under supervision at the time - meaning the offending rate was 5.8%.
The statistics were detailed for the first time in its annual report, published on Monday.
The findings come at a time when the board is seeking to increase its independence from the government.
Between April and September, there were 901 requests by life sentence prisoners, including murderers and rapists, to be released after serving their minimum term.
Only 106 of these were granted.
Previously, about one in five prisoners serving life sentences were released.
Parole Board chairman Sir Duncan Nichol said the figures showed that police and probation staff were "enforcing breaches of release conditions more rigorously and were being more attentive to risk".
He added that his members were being more cautious after two high-profile cases in which violent offenders committed murder after being released from jail.
"We have taken another good hard look at the violent offender who has been a 'model prisoner'," he said.
"We will be absolutely sure before we release."
According to the report, the other former prisoners who had not committed offences had been recalled for being out of touch with probation staff, refusing to live at a bail hostel as required, or failing to comply with release conditions.
The overall recall rate for those serving life sentences was 9.4% in 2005/6 - compared with 6.6% the previous year and 3.8 % the year before that.
Timeline: Anthony Rice
Anthony Rice, 48, strangled and stabbed Naomi Bryant, 40, in August 2005
Rice, who had previous convictions for indecent assault and rape, had been given a 10-year minimum term in 1989 for attempted rape
Two parole requests were turned down before he was released in November 2004
The Parole Board said he was a "minimal risk"
The report's figures also showed the number of former prisoners serving fixed sentences sent back to prison was also a record 993 - one in five prisoners on parole.
Of those, 302 were recalled for committing further offences.
Sir Duncan said that Home Secretary John Reid's "exhortations" to put public protection first had also impacted on the numbers of prisoners granted release.
The chairman said the fairness of the Parole Board's decisions could be called into question while it continued to remain under Home Office.
He is calling for the responsibility for his organisation to be transferred away from the government department.
Sir Duncan's comments follow the chief inspector of probation, Andrew Bridges' criticism of the release of sex attacker Anthony Rice, who strangled and stabbed Naomi Bryant, 40, in her home in Winchester in August last year.
The Parole Board concluded Rice presented only a "minimal risk"
Rice killed her nine months after he was freed by the Parole Board, who deemed the risk to the public to be minimal.
In his report in May, Mr Bridges said the prison and other officials in Hampshire, were "side-tracked by considering Rice's human rights above their duties to the public".
Paul Cavadino, chief executive of the crime reduction charity, Nacro, said public safety "must be paramount in parole decisions", but emphasised the possibility of rehabilitation.
"However, it would be regrettable if the pendulum swung too far under media or political pressure and led to prisoners who could safely be released under supervision remaining inside."
Parole allows a prisoner to be released before they have served their full sentence, which is granted on the basis of reports by prison and probation staff.
A prisoner can apply for parole six months before their parole eligibility date (PED).
In the case of a prisoner serving 15 years or more, or someone who was sentenced before 1 October 1992, the case will be referred to the Home Secretary for a decision.